well, if you figure that the average 'stat' in the game is suppose to be '3' for a normal human, pushing the maximum penalty to anything over 6 would have to be a near-totally fatal flaw, or 'the strength of 10 men' edge.
the way I look at it, a level '3' flaw, should be restrictive enough to lower effectivly three of your stats by '1' or one of your stats by '3'
a level 6 flaw should be able to take the thing you are best at (level six skill) and reduce it to nothing.
whereas a level 6 edge would effectivly double your range on a level 6 skill.
a code of ethics... *shrug* depending on the code I'd probibly say that's a one or two point flaw.
sense of duty would probibly be worth about three points. it's certanly more risky than 'daredevil' (having to rescue every little old lady would be a pain in shadowrun)
but then again, I know guys that play that way for free.
*shrug*
-RuskiFace the Pirate